The present invention relates to a method of local ventilation, a ventilation method, a local ventilator, and a ventilating system, and more particularly to local ventilating and ventilating technologies which are effective when a contaminant that causes air contamination is released from a specific indoor portion, and the contaminated air is heat draft, steam, odor, tobacco smoke, lamp soot, or dusty air that is not harmful to human body, in all indoor spaces necessary to be ventilated such as factories, kitchens, smoking rooms, and bathrooms.
Generally, indoor spaces such as factories, kitchens, smoking rooms and bathrooms, where there exists a point of release of a contaminant that causes air contamination, must be provided with ventilation for cleaning the indoor atmosphere.
In this case, as a method of ventilating indoor spaces in which the contaminated air released is heat draft, steam, odor, tobacco smoke, lamp soot, or dusty air that may not endanger lives, generally employed is a so-called overall ventilation system which is arranged that the whole air in the room is replaced while the contaminated air is in a state of being mixed and diluted in the indoor atmosphere.
As an overall ventilation system, there are three types of systems such as a system using mechanical power for both air intake and discharge, a system using mechanical power for air intake only, while discharging the exhaust air from an exhaust hole in a spontaneous fashion, and a system using mechanical power for discharging the air only, while taking in the air from an air intake port in a spontaneous fashion. Usually, however, a mechanical ventilation system using suction draft created by mechanical power is mainly employed.
Regarding the legal standards related to ventilating apparatuses for general buildings, the amount of ventilation is specified for the purpose of assuring safety and sanitation aiming at humans according to the result of calculation from the allowable concentration of indoor carbonic acid gas, and for the purpose of assuring the amount of oxygen necessary for combustion in a room where a fire is used. Actually, however, there are no clear standards based on true technology and performance. And, in the technical field or industry of buildings at present, to install an inexpensive ventilating system without spending much money, which just meets the requirements of the legal standards related to ventilating apparatuses, is a common method widely employed.
A general ventilating system for rooms that require reasonable habitability and workability, for example, a ventilating system for kitchens is arranged, as shown in FIG. 8, having a configuration of an overall ventilation system for ventilating the entire room of the kitchen such that combustion heat type cooking equipment a, the point of release of contaminant, is installed near the room wall.
That is, in the ceiling above the cooking equipment a is provided suction hole c of exhaust duct b, and also an exhaust duct fan (not shown) is disposed at the outdoor end portion of the exhaust duct b. Also, exhaust hood e for catching the contaminated air made up of heat jet d of the contaminant generated due to combustion heat of the cooking equipment a is connected to the suction port c in order to prevent the diffusion of the contaminated air. On the other hand, in the ceiling at the center of the room, remote from the cooking equipment a, is disposed air intake port h of air intake duct g provided with air box f, and also air conditioner i is installed near there. Further, exhaust duct k provided with exhaust ceiling fan j is disposed on the ceiling near opening m remote from the cooking equipment a.
And, the heat jet d of the contaminant generated due to combustion heat of the cooking equipment a is caught by the exhaust hood e and collected into the exhaust duct b from the suction port c as the exhaust duct fan of the exhaust duct b is operated, and then it is discharged out of the room, while the room air at the portion remote from the cooking equipment a is discharged out of the room through the exhaust duct k disposed near the opening m as the exhaust ceiling fan j is operated. On the other hand, from the air intake port h at the center of the ceiling, outside fresh air is taken in through the air box f of the air intake duct g as an intake duct fan (not shown) is operated, while fresh air also spontaneously flows into the room from the window (opening) m of the kitchen. In this way, the entire room of the kitchen is ventilated.
However, in such an overall ventilation system, there arise many problems as mentioned in the following, and there has been a demand for their improvements.
That is, as represented by kitchens, when an overall ventilation system is employed for a room in which a lot of contaminant is released, the amount of ventilation becomes very large and it will worsen the efficiency of ventilation, and also, the state of the air in the room becomes identical with that of the outside air because a large volume of atmospheric air is taken into the room.
Further, in ventilation based on suction draft with use of mechanical power, it is unable to effectively discharge only the contaminant because of poor controllability, and it will cause the heat, steam, lamp soot, odor, fume or the like to be detained in the room, and then the room air condition comes to the worst.
For example, in the case of kitchens, the ventilating air volume and air conditioning capacity required will become very large if intended to satisfy the kitchen temperature and humidity conditions, that is, the standards of HACCP (Hazard Analysis and Critical Control Point) system.
And, the considerable increase of ventilating air volume and air conditioning capacity means that the capacities of ventilating and air conditioning apparatuses are increased resulting in increase of the initial cost and running cost of the ventilating and air conditioning apparatuses.
Also, the increase of the equipment capacities of ventilating and air conditioning apparatuses means that the electric capacity of the equipment is totally increased and such increase in the amount of energy used will invite the increase of the generation of global warming gas such as CO and CO2.
In this respect, it is possible to employ a ventilating system for special purposes as mentioned below as a ventilating system for rooms that require reasonable habitability and workability, such as a ventilating system for kitchens.
That is, in factory ventilation, since the legal standards are very strict because of generation of contaminants harmful to human body, a method of partial or local ventilation by using a draft chamber is employed as an effective method in which the point of release of harmful contaminant is surrounded by partitions and the worker performs the work by inserting the hands through the partitions.
Further, in case the work does not allow the use of such draft chamber, a so-called push-pull uniform flow system is employed as an effective method of local ventilation. In a local ventilation method by this push-pull uniform flow system, the point of release of the contaminant is wrapped up with the uniform flow of blowout (push) draft and suction (pull) draft, and thereby, the air balance is locally completed.
On the other hand, as an overall ventilation system for ventilating a large space such as a parking garage, a so-called delivent ventilation system using an inductive action is also available. In this delivent ventilation system, a plurality of small fans which guide and deliver the contaminated air of the room to the exhaust port, corresponding to the suction exhaust, are installed in good order. By this ventilating system, it is possible to shorten the extension distance of the duct and also to efficiently perform the ventilation.
However, even in such a local ventilation system effective for special purposes, and an overall ventilation system, there will arise other problems as mentioned below if employed as a ventilating system for rooms that require reasonable habitability and workability, and therefore, they have not yet been materialized.
That is, in a local ventilation method by using a draft chamber, the point of release of the contaminant is surrounded by partitions, and there is no fear of leakage of the contaminated air into the room, but the workability will extremely worsen because getting things in and out of the working place can be done only through the door.
Also, in the case of a local ventilation method by a push-pull uniform flow system, since the blowout draft and suction draft are balanced with each other in speed and volume with respect to the entire ambient space, the bore diameters of the blowout port and the suction port become larger, and at the same time, the volume of air becomes very large. Also, from the workability point of view, the worker gets in the uniform draft, and in the case of a kitchen, unlike the above suction port, disposing a blowout port at the lower position will not only affect the workability but also result in remaining of a problem in terms of sanitation.
Further, a method of ventilation by a delivent ventilation system is not a method of local ventilation but a method of overall ventilation, in which the contaminated air is guided in the direction of ventilation, supposing that the car exhaust is accumulated and detained at the ceiling of the parking garage, and as a result, it is possible to improve the ventilating efficiency but unable to reduce the volume of air. Also, the level of noise is very high because many small delivent fans are installed on the ceiling.
The present invention is intended to solve such conventional problems, and the object of the invention is to provide ventilation technology with which local ventilation may be completed without affecting the habitability and workability.
Also, another object of the present invention is to reduce the amount of ventilation and the air conditioning capacity, that is, to provide ventilation technology with which it is possible to reduce the initial cost and the running cost of the ventilating and air conditioning equipment by avoiding a waste of electric energy and decreasing the equipment capacity, and consequently, to decrease the generation of global warming gas.
In order to achieve the above purpose, the local ventilation method of the present invention is a method of locally discharging the air around and near the point of release of the contaminated air, which is characterized in that upward suction draft going out of the room is produced from a position above the point of release of the contaminant, while upward blowout draft is produced from a position near the side of the point of release of the contaminant, and due to the inductive action of the blowout draft, the contaminated air around and near the point of release of the contaminant is forcibly caught and carried into the above blowout draft.
Also, the ventilation method of the present invention is a method of ventilating a room where there exists the point of release of a contaminant that causes the air to be contaminated, which is characterized in that the local ventilation method is applied to the point of release of the contaminant in order to establish the balanced ventilation of the room.
As a preferred embodiment, auxiliary blowout draft that passes so as to wrap up the point of release of the contaminant is produced from a portion around the ventilating zone to which the local ventilation method is applied, and the contaminant generated from the point of release of the contaminant is forcibly caught and carried into the upward uniform draft formed by the blowout draft and the suction draft.
Also, the local ventilator of the present invention is preferably employed for the execution of the local ventilation method, comprising a suction draft producing means for producing upward suction draft going out of the room, with a suction port provided above the point of release of the contaminant, and a blowout draft producing means for producing upward blowout draft, with a blowout port provided in a position close to the side of the point of release of the contaminant, and due to the inductive action of the blowout draft produced by the blowout draft producing means, the contaminated air around and near the point of release of the contaminant is forcibly caught and carried into the blowout draft.
As a preferred embodiment, the blowout port of the blowout draft producing means is disposed facing upward at a position near the side of the point of release of the contaminant isolated from the working position of the worker. Also, preferably, a draft rectifying means for preventing the diffusion of blowout draft produced by the blowout draft producing means is disposed at a position below the suction port of the suction draft producing means. Further, a blowout port is disposed at a position above the point of release of the contaminant, which comprises an auxiliary blowout draft producing means for producing downward auxiliary blowout draft that passes so as to wrap up the point of release of the contaminant.
Further, the ventilating system of the present invention comprises the local ventilator to cope with the point of release of contaminant and is characterized in that the ventilation of the room is balanced due to the configuration.
As a preferred embodiment, there is provided a blowout port at a position around the ventilating zone of the local ventilator, which comprises an auxiliary blowout draft producing means for producing auxiliary blowout draft that passes so as to wrap up the point of release of the contaminant.
In the local discharge and ventilation of the present invention, highly controllable upward uniform draft, passing around and near the point of release of contaminant that causes the air to be contaminated, is created by the suction draft and the blowout draft, and at the same time, due to the inductive action of the blowout draft, the contaminated air around and near the point of release of the contaminant is forcibly caught and carried into the blowout draft.
In this way, the local discharge and ventilation can be completed, without wrapping up the point of release of the contaminant, as the upward uniform draft that forcibly discharges the contaminated air passes around and near the point of release of the contaminant. As a result, there will be no interference with the operation of the worker nor hindrance to the habitability and workability.
Also, by completing the local discharge and ventilation, it becomes possible to reduce the amount of ventilation and the air conditioning capacity, and as a result of keeping the capacity of ventilating and air conditioning equipment at a low level, it is possible to decrease the initial cost and running cost of the ventilating and air conditioning equipment, and also to reduce the consumption of electric energy, thereby enabling the reduction of the generation of global warming gas.